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| Description: One plus one equals two. Using proof-shortening techniques pioneered by Mr. Mel O'Cat, along with the latest supercomputer technology, Prof. Loof Lirpa and colleagues were able to shorten Whitehead and Russell's 360-page proof that 1+1=2 in Principia Mathematica to this remarkable proof only two steps long, thus establishing a new world's record for this famous theorem. (Contributed by Prof. Loof Lirpa, 1-Apr-2008.) |
| Ref | Expression |
|---|---|
| 1p1e2 |
|
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | df-2 7154 |
. 2
| |
| 2 | 1 | eqcomi 1888 |
1
|
| Colors of variables: wff set class |
| Syntax hints: |
| This theorem is referenced by: zgt1b2 13772 isprm3 13776 2prm 13779 pco1 16078 pcohtpy 16083 pcorev 16087 |
| This theorem was proved from axioms: ax-1 4 ax-2 5 ax-3 6 ax-mp 7 ax-gen 1305 ax-4 1319 ax-5o 1321 ax-ext 1865 |
| This theorem depends on definitions: df-bi 164 df-an 242 df-cleq 1877 df-2 7154 |